An intensive two-week course is proposed for advanced graduate students, medical students, postdoctoral fellows, medical research fellows and independent investigators that will focus on the development and genetics of zebrafish with special emphasis on the nervous system. The first week of the course will cover the early development and genetics of zebrafish and the relevant methodologies, whereas the second week will focus on the nervous system. Mornings will be devoted to lectures and discussion and afternoons to 3-4 hour laboratory exercises. Each day will be under the supervision of a senior faculty member who will be assisted by one or two more junior faculty members. The course will be limited to 12-16 students. Lectures in the first week will cover the developmental stages of zebrafish, chemical and insertional mutagenesis, early development and organogenesis and zebrafish husbandry. In the second week, the students will be introduced to the nervous system of zebrafish, its development and the analysis of nervous system mutants. Specific areas to be covered in the second week include the fore- and hindbrain, spinal cord, eye and retina, tectum and aspects of zebrafish behavior. Laboratory exercises in the first week will introduce students to developing wild- type and mutant embryos, techniques of nucleic acid injection, cell transplantation, in situ hybridization, and the labeling of single cells. In the second week, students will dissect the zebrafish nervous system, study brain histology, perform behavioral tests on wild-type and mutant animals, and learn axonal pathfinding techniques.